A modularized circuit board mounting architecture is proposed, which is designed for use to mount a modularized circuit board onto the inside of an enclosure, such as a server's chassis or a desktop computer's casing. The proposed mounting architecture is more advantageous to use that prior art in that the mounting and dismounting of the modularized circuit board to and from the enclosure can be both carried out effortlessly simply by hand without requiring technical personnel or user to use any assisting tools, such as screw drivers. This feature allows computer manufacturers to assembly computer units more quickly and efficiently and thereby significantly reduce labor hours. Moreover, it also allows after-sale maintenance or upgrade to be carried out more quickly and efficiently.